Electrical protective apparatus



Dec. 12, 1933. s. J. sPURGEoN ELECTRICAL PRTECTIVE APPARATUS Filed Oct. 27, 1930 IN1/EN TOR.

Patented Dec. 12, 1933 UNITED STATES PATENT OFFICE This invention relates to equipment known as high-voltage fuses and lightning arresters, and the purpose is to make a single compact unit which provides a path to ground for high-frequency or over-voltage surges, and also gives automatic fuse protection in case of continued over-load on the line.

Referring to the drawing, the single ngure is a side elevation of my device shown partly in crosssection. Clamped to a wooden cross arm is a pair of straps 1, 2 upon one of which are mounted two separate insulators 3, 4. These carry, respectively, two metal terminals 5, 6 to which the incoming line '7 and the conductor to the transformer 8 are connected, respectively.

An insulating tube 9 in which is atusible conductor, is pivoted on 6 and caught under the spring latch l0. Good contacts are assured by the spring brush members 11, 12. The fusible conductor is attached to the pivoted latch 13, and when the fusible member ruptures 13 becomes disengaged from 10 and 9 drops to the position 14. Also the member 9 may be used as a disconnecting switch if desired. The operator merely hastoraise the spring latch 10 by means ofvan insulating stick, and the member 9 with fuse intact swings to the position 14.

The insulator 4 is tubular and within it are parts which form the lightning arrester. A set of discs 15 form a path of limited capacity over which high-frequency or high-voltage discharges of moderate amperage can pass to the gap 16, and so through the strap 2 to a ground connection not shown.

With this device in the circuit between the main line and a transformer, any overload-or short circuit on the transformer would be cleared by the rupture. of the fuse in 9 and the subsequent removal of the tube by gravity to 14. This is a well known method of protection.

Now, if a high-voltage surge comes down over the conductor '1, the arrester 15, 16 gives a direct path for the surge to ground, thereby saving the transformer. that the usefulness of the parts 15 or 16 should be destroyed, then the fuse in 9 would again serve to clear the line, and service could be resumed everywhere except on the translormer to which 8 is connected.

Present practice is to use some sort of fuse apparatus to protect the transformer against overload, and have the lightning arrester installed as a separate unit connected between the line 'I and the ground. This requires the mounting ot two units instead of one, and also incurs the risk that Also, if the surge shouldbe so heavy 50h-ima. (CL 2MP-115) trouble on the lightning arrester may cause a shut-down of the entire circuit from which 'I is supplied with power.

My unit may be installed under various other conditions without departing from the spirit and purpose of my invention.

I claim:

l. In a protective device, the combination' of two spaced insulators each with a conducting terminal mounted thereon, an expulsion-tube spanning the terminals, a fuse within the expulsion-tube, and members of a lightning arrester housed within one of the insulators.

2. In a protective device, the combination of a common conducting base carrying two spaced insulated terminals, a removable tubular fuse container pivotally mounted upon one of the terminals and latched into contact with the other terminal, and a lightning arrester mounted upon the common base and connected with one of the terminals.

3.- In a protective device, the combination of two spaced insulators, terminals thereon, a removable expulsion-tube fuse container pivotally mounted upon one terminal and in contact relation with the other terminal, a fuse within the container, and a lightning arrester housed within one of the insulators.

4. In a protective device, the combination of two spaced insulators, terminals thereon, an expulsion-tube fuse container pivotally mounted upon one terminal and latched into contact with the other terminal, a fuse within the container, and a lightning arrester housed within one of the insulators.

5. In combination, a fuse within an expulsiontube which is supported upon two separate insulators, one of which insulators is also a housing containing a lightning arrester.

SAMUEL J. SPURGEON. 

